1. Field of the Invention
The present invention relates to a device for simulating crash scenarios. Such devices are especially used for simulating the effects of a crash on a test object and are also referred to as crash test sled devices.
2. Description of Related Art
In order to test the crash behavior of vehicles and the effects of the impact on specific parts of the vehicle, crash tests with complete vehicles have always been made. For this, the vehicles are accelerated and caused to collide with stationary obstacles. This has normally the effect that the vehicle in question is destroyed completely. Crash tests with complete vehicles are, by nature, very expensive. Therefore, so-called crash sleds have already been used for quite some time. A difference is made between acceleration sleds and deceleration sleds. Deceleration sleds are carefully accelerated to a specific speed by means of a suitable accelerating device and are then decelerated comparatively abruptly by a decelerating unit so as to simulate the impact. When a so-called acceleration sled is used, the impact is, however, simulated inversely. The sled is first standing still and is then accelerated backwards by a very powerful accelerating unit. In either case, the vehicle superstructures to be tested are installed on the sled.
Simple crash sled devices can only reproduce accelerations acting in an axial direction. In most crashes, the acceleration behavior will, however, be complex. The vehicle not only undergoes strong negative acceleration in the longitudinal direction. Depending on how the vehicle collides with the obstacle, also pitching, yawing and rolling movements will occur.
A crash sled device, by means of which pitching as well as yawing movements can be simulated, is known, e.g., from DE 102007056572 A1. The crash sled of this device comprises a lower part and an upper part serving as a carrier for the components to be tested. The upper part rests at the front and at the rear end of the sled on a respective traverse member. The two traverse members can be vertically adjusted independently of one another by means of actuators, so that a pitching movement can be imparted to the upper part of the sled. The upper part of the sled and the two traverse members are supported in sliding contact with one another. The upper part can therefore be moved on the traverse members in a transverse direction. For this, appropriate actuators are provided at the front end as well as at the rear end of the sled. The front end and the rear end of the upper part can thus be moved in a transverse direction independently of one another. A yawing movement about the vertical axis of the sled can be generated in this way. A rolling movement can, however, not be simulated. Moreover, tests have shown that the device disclosed in DE 102007056572 A1 is unsuitable for heavy test objects and great impact loads.
Also DE 102007042775 A1 discloses a two-part crash sled. The upper platform of the sled is configured such that it is able to execute a pitching movement relative to the lower part. For this, two actuators are provided, by means of which the front end and the rear end of the upper platform can be vertically adjusted independently of each other. The device is not suitable for simulating yawing or rolling of the upper platform. A similar device is known from DE 102005010189 B3.
Also the crash sled devices according to DE 19857429 A1 and DE 10118682 B4 allow a pitching movement of the sled. In both cases, the actuators used for vertically adjusting the front and the rear end of the crash sled are either partly or fully integrated in the base and are therefore not disposed between the upper part and the lower part of the sled. Also these devices are unsuitable for simulating yawing or rolling movements.
DE 19805512 B4 discloses a two-part acceleration sled provided with a tilting mechanism in the form of a passive hydraulic unit. The hydraulic unit allows a pitching movement of the upper part of the sled, the forces occurring during the pitching movement being partially absorbed. The publication describes that e.g. a rotational movement of the test setup about the vertical axis of the sled can be superimposed on the pitching movement. A suitable device configured for simulating pitching and yawing movements is, however, not shown.
EP 2098850 A2 discloses a sled for executing crash tests with a dummy. The dummy is secured in position on a platform which is capable of carrying out a secondary movement relative to the actual sled, said secondary movement being superimposed on the impact deceleration. For generating the secondary movement, an actuator unit is provided between the dummy platform and the sled. The sled shown in EP 2098850 A2 is, however, not suitable for heavy test objects and great impact loads.